With regard to prior rubber-surface treatment agents, Japanese Patent Application Laid Open No. 57-111394 [111,394/82] discloses a lubricating composition for the bladders used in tire manufacturing. This composition comprises polydimethylsiloxane, alkoxysilane, and a zinc catalyst.
In addition, Japanese Patent Application Laid Open No. 60-17911 [179,211/85] also discloses a lubricating composition for tiremaking bladders, in this case comprising a polymer emulsion prepared from alkoxysilane and hydroxyl-terminated diorganopolysiloxane.
However, the dimethylpolysiloxane in the composition described in Japanese Patent Application Laid Open No. 57-111394 is in fact not a dimethylpolysiloxane terminated at one end by the hydroxyl group or an alkoxy group and terminated at the other end with a triorganosiloxy group. As a consequence, it is only weakly reactive with rubber surfaces, which results in a poor adhesion, and it also has poor lubrication properties.
Furthermore, because a catalyst is not used for the composition described in Japanese Patent Application Laid Open No. 60-179211, the crosslink density is so low that a durable lubrication cannot be obtained.
The object of the present invention is to solve the problems listed above by introducing a rubber surface-treatment composition which will generate a durable release activity and durable lubrication by virtue of its reaction with the rubber surface and the formation of crosslinkages during curing.